When using a computer system having a modern graphical operating system, it is often desirable to view a preview of a document. A document preview is a rendering of a document that mirrors what the user will see when the document is opened with an application program associated with the document. A document preview, however, is generated and displayed without actually opening the document for editing.
Some application programs allow a user to view a static thumbnail image of a document. However, such static images are not generated dynamically, and are therefore not a true document preview that a user can page through or navigate. Other programs require a user to launch an application program associated with the document to view its contents. For instance, within an electronic mail (“e-mail”) client application program, it is sometimes desirable to view a preview of one or more documents attached to an e-mail message. Current e-mail application programs, however, require a user to launch the application associated with the attached document to view the document. This process can be time consuming and frustrating for a user.
In addition to being able to view a document preview from within an application program, it also may be desirable to view a document preview from within the context of an operating system program, such as a graphical desktop shell. For instance, when a user utilizes the shell to navigate to a folder containing documents, it may be desirable for the user to quickly view a preview of the documents without the need to launch an associated application program. Similarly, it may be desirable to quickly view a document preview in the context of a dialog box utilized for opening files. In this manner, a user could view a document preview and quickly examine the contents of the document without the need to open an application program associated with the document. However, in order to preview documents utilizing current systems, each application program and operating system must implement their own framework and code for previewing documents.
It is with respect to these considerations and others that aspects of a computing system for generating document previews are described below.